[Genetic basis of tobacco dependence].

Dependence on tobacco is one of the most important health problems in our society due to the direct relationship with lung cancer. Early studies in twins revealed that genetic factors modify the susceptibility to develop tobacco dependence. Different studies are underway to try to find an association between polymorphisms of genes involved either in nicotine metabolization or in neural transmission and the initiation and maintenance of the dependence on tobacco. Here we review the studies performed so far and discuss new perspectives for future studies.